The present invention relates to measurement of spherical aberration, and more particularly, to a method of employing a non-interferometric technique, making use of axial intensity information, in which the intensity of the light pattern along the optical axis is calibrated to achieve improved measurement of spherical aberration, and an apparatus for practice of same.
Spherical aberration is measurable via a number of experimental procedures. Qualitative and semi-qualitative estimates can be obtained by the visual inspection of the star image, or from a Foucault knife edge test. Quantitative methods include the Hartmann test, and a host of interferometric approaches, such as point diffraction, and lateral shear interferometry. However, such methods are known to be inaccurate, difficult to apply, and time-consuming in various applications.
It is therefore an object of the present invention to provide a novel method for accurate direct measurement of spherical aberrations in test pieces.
It is another object of the present invention to provide a novel apparatus for practice of the invention.